Extracorporeal isolated pig liver perfusion: influence of various blood primes on liver function

Extracorporeal isolated pig liver perfusion was performed in three groups of five piglets each to assess the influence of different blood primes on liver function. All prime volumes were hemodiluted to a hematocrit of 0.3-0.35 and adjusted to a pH of 7.35-7.45 with sodium bicarbonate at a temperature of 38 degrees C. Fresh slaughterhouse blood was collected, mechanically filtered and used in Group A, whereas analogously collected blood was biologically filtered by passage through the organism of the piglet in Group B. In Group C, the priming blood consisted of autologous blood gained during hepatectomy by a special technique. A high potassium concentration (10.4 +/- 0.94 mmol/l) in Group A and impurities of the slaughterhouse blood in both Groups A and B led to rapid edema formation and an increase in vascular resistance of the perfused liver, and a prolonged perfusion was not achieved. In the third group, however, liver perfusion over a period of 5 h without any deterioration of liver function was possible. Beside liver function tests, oxygen consumption, the macroscopic aspect and bile flow of the liver seemed to be the most reliable parameters in assessing the function of the isolated perfused pig liver. Our technique to gain autologous blood can be recommended not only for extracorporeal liver perfusion but also for any other extracorporeal isolated organ perfusion.